feat(aio): first pass API docs redesign (#21874)

Includes:

* display ToC for API docs
* update dgeni-packages to 0.24.1
* add floating sidebar in API docs
* add breadcrumbs and structured data for Google crawler
* improved rendering of method overloads
* properties rendered in a table
* params rendered with docs
* removal of outdated "infobox" from all API docs

PR Close #21874

aio/tools/transforms/angular-api-package/processors/processClassLikeMembers.js

@@ -0,0 +1,59 @@
+/**
+ * A class like API doc contains members, but these can be either properties or method.
+ * Separate the members into two new collections: `doc.properties` and `doc.methods`.
+ */
+module.exports = function processClassLikeMembers() {
+  return {
+    $runAfter: ['filterContainedDocs'],
+    $runBefore: ['rendering-docs'],
+    $process(docs) {
+      docs.forEach(doc => {
+        if (doc.members) {
+          doc.properties = [];
+          doc.methods = [];
+          doc.members.forEach(member => {
+            if (isMethod(member)) {
+              doc.methods.push(member);
+              computeMemberDescription(member);
+            } else {
+              doc.properties.push(member);
+
+              if (!member.description) {
+                // Is this property defined as a constructor parameter e.g. `constructor(public property: string) { ... }`?
+                const constructorDoc = member.containerDoc.constructorDoc;
+                if (constructorDoc) {
+                  const matchingParameterDoc = constructorDoc.parameterDocs.filter(doc => doc.declaration === member.declaration)[0];
+                  member.constructorParamDoc = matchingParameterDoc;
+                }
+              }
+            }
+          });
+        }
+        if (doc.statics) {
+          doc.staticProperties = [];
+          doc.staticMethods = [];
+          doc.statics.forEach(member => {
+            if (isMethod(member)) {
+              doc.staticMethods.push(member);
+              computeMemberDescription(member);
+            } else {
+              doc.staticProperties.push(member);
+            }
+          });
+        }
+
+      });
+    }
+  };
+};
+
+function isMethod(doc) {
+  return doc.hasOwnProperty('parameters') && !doc.isGetAccessor && !doc.isSetAccessor;
+}
+
+function computeMemberDescription(member) {
+  if (!member.description && member.overloads) {
+    // Perhaps the description is on one of the overloads - take the first non-empty one
+    member.description = member.overloads.map(overload => overload.description).filter(description => !!description)[0];
+  }
+}